Frequent deadly attacks by insurgents sapped morale and raised combat stress in a U.S. Army platoon that included soldiers accused of raping and murdering a 14-year-old Iraqi girl, a member of the unit testified Tuesday.

Pfc. Justin Cross recounted the "mentally draining" conditions in which the unit served in Mahmoudiya south of Baghdad where Abeer Qassim al-Janabi was raped and killed along with her parents and 5-year-old sister.

"It drives you nuts. You feel like every step you might get blown up. You just hit a point where you're like, 'If I die today, I die.' You're just walking a death walk," Cross told the hearing.

Spc. James P. Barker, Sgt. Paul E. Cortez, Pfc. Jesse V. Spielman and Pfc. Bryan L. Howard are accused of raping the girl, and murdering her and the other three. Another soldier, Sgt. Anthony W. Yribe, is accused of failing to report the attack but is not alleged to have been a direct participant.

CountryWatch: Iraq

The ongoing hearing will determine if they should be court martialed. If convicted by a court-martial, the five could face the death penalty.

On Tuesday, lawyers for the four main accused demanded a new hearing, accusing Yribe's counsel of deliberately asking incriminating questions. A ruling was expected later in the day.

A sixth soldier in the unit, former Pfc. Steven D. Green, was discharged from the Army for a "personality disorder" after the incident and was arrested in North Carolina in June on rape and murder charges. He has pleaded not guilty in federal court and is being held without bond.

All were assigned to the same platoon of the101st Airborne Division from Fort Campbell, Kentucky.

On Tuesday, Cross testified that soldiers often drank Iraqi whiskey and took painkillers to relieve the stress of not knowing whether the day would be their last.

Mahmoudiya, about 20 miles south of Baghdad, is one of the most dangerous places in Iraq, where bomb and gun attacks by insurgents take place almost daily.

Cross said the unit was "full of despair," and he himself felt he would die at a checkpoint before he could go home.

"I couldn't sleep mainly for fear we would be attacked," Cross said. He said the loss of two soldiers shot at a checkpoint "pretty much crushed the platoon."

Cross testified that Barker, who obtained the Iraqi whiskey, drank the most. He said he knew Green also was taking painkillers even though he never saw him.

"Everybody was very depressed. It was (an) outlet to release," Cross said.

Army criminal investigator Benjamin Bierce testified Monday about a sworn statement by Barker in which he spoke about a drinking session before the assault on the girl's house.

Bierce said Barker confessed in his statement that he, Cortez and Green took turns raping Abeer. Barker also claims in his graphic statement full of sexual details that Green shot and killed the girl and her family members.

Another witness, Pfc. Justin Watt, testified Monday that that he heard Green say: '"I want to kill and hurt a lot of Iraqis."' Watt also said that he didn't believe Green "could have done this all by himself."

Watt's comments were made during questioning by Yribe's lawyers.

On Tuesday, defense lawyers said they had attributed such questioning to incompetence by Yribe's lawyers. But a similar line of questioning was followed with another witness again on Tuesday as part of the Yribe team's ongoing bargaining with the government, said defense lawyers Capt. James Culp and David Sheldon.

They said their clients' case has been undermined.

The rape and murders have bolstered allegations of misconduct by soldiers including illegal killings, beatings and inhuman treatment. The allegations have increased the mistrust and resentment among Iraqis of the American military and increased calls for their withdrawal.

Since the case became public last month, U.S. officials have said they were concerned it could strain relations with Iraq's new government if Iraqis perceive that the soldiers receive lenient treatment.

They have offered assurances that the case will be pursued vigorously and that the soldiers will be punished if convicted.

The case has already increased demands for changes in an agreement that exempts U.S. soldiers from prosecution in Iraqi courts. And Prime Minister Nouri al-Maliki has demanded an independent investigation into the Mahmoudiya allegations.